Easy BITX Troubleshooting: Step 3 TX and RX Rails

Easy BITX PCB is densely populated and dual sided. So I found it difficult to identify the component connections on the reverse side where only a few SMD components have been mounted. Voltages can be checked easily only from that side. I had photographs of the PCB which were taken before assembling the kit. So I mounted pictures of both sides on a powerpoint slide and viewed it in my 32 inch monitor to make it easier for me to view the connections. Then I marked the pin numbers of the J8 connector which has 40 pins on both sides of the PCB picture as you can see here. From the schematic, I could find that pin 23 goes to the RX+ and pin 18 to the TX+ lines. There is also a line from pin 8 to T1 transformer. BAT54S SMD diodes can be seen in that region, which serves as product detector for RX and balanced modulator for TX. Three pins at three corners of a triangle can be identified as those of CV1 trimmer capacitor of the balanced modulator. Just near that three pins of Q1 transistor could also be identified and marked. With this much information at hand, I proceeded with checking the RX+ and TX+ rails as well as the voltages of emitter, base and collector of Q1 transistor. Emitter can be seen as grounded on the PCB. In an RF PCB, all the bulk green you see are the PCB ground.